#include<stdio.h>

int main(){
    double sum = 0;
    for(int i = 0;;i++){
        double term = 1.0/(i*2+1);
        if(i%2==0) sum+=term;
        else sum-=term;
        printf("%.6f\n",sum);
        printf("%.6f\n",term);
        if(term<1e-6)break;
    }
    printf("%.6f\n",sum);
    return 0;
}